window.onload = function(){
            getRem(750,100)
        };
        window.onresize = function(){
            getRem(750,100)
        };
        function getRem(pwidth,prem){
            var html = document.getElementsByTagName("html")[0];
            var oWidth = document.body.clientWidth || document.documentElement.clientWidth;
            html.style.fontSize = oWidth/pwidth*prem + "px";
        }
